BEYMA WL3/Fe

Beyma WL3/Fe: 0.8" compression driver with waveguide, ferrite magnet and 70 W AES

The Beyma WL3/Fe is a compression driver with an integrated waveguide from Beyma's WL series. Throat 0.8", ferrite magnet, 70 W AES power handling, 5 Ω nominal impedance and a resonance frequency of 1,000 Hz. Unlike a conventional compression driver with a screw-on or bolt-on throat, it comes with its waveguide attached – the whole unit mounts into the baffle. That removes the horn selection and the question of matching throat diameters.

Within the WL series the WL3/Fe is the variant with the highest resonance frequency: an Fs of 1,000 Hz implies a compact diaphragm and a waveguide aimed at the upper midrange and treble. The ferrite motor makes it heavier than a neodymium version, but it is immune to thermal drift and no disadvantage in fixed installation. The 0.8" throat is smaller than on the common 1" drivers; that favours even directivity up to the highest frequencies because the transition from throat to waveguide begins earlier, but it costs diaphragm area and therefore power handling at the lower end.

Use and enclosure

The rule of thumb for compression drivers applies: crossover at least one octave above Fs, so clearly above 1,000 Hz here, with a steep slope – with 70 W AES and a small diaphragm, a passive 12 dB filter is the minimum and an active 24 dB/octave filter safer. That makes the WL3/Fe a partner for small mid-bass drivers in 2-way cabinets, columns and compact monitors where a 1" driver with a separate horn would be too deep. It also sits sensibly in 3-way systems as a pure tweeter above a midrange.

The 5 Ω nominal impedance is unusual but harmless in practice: any amplifier that drives 4 Ω loads will cope. With a passive crossover you have to use the 5 Ω in the component calculation, otherwise the crossover frequency shifts. Level matching to the woofer is done as usual with a voltage divider or L-pad. Further Beyma compression drivers and the matching horns and waveguides are listed in the driver database on 42.audio.

What to look out for

• 5 Ω nominal: run from 4 Ω-capable amplifiers, account for it in the crossover
• Fs 1,000 Hz: cross over well above, with a steep slope
• 70 W AES: sized for small 2-way cabinets and monitors
• Ferrite magnet: heavier than neodymium but thermally stable
• Waveguide integrated – no separate horn required

Frequently asked questions

At 42.audio you get the BEYMA WL3/Fe with all key data in the driver database. More drivers from this manufacturer: Atlas Beyma.